/**
 * PlayGame prompts the user for input and interacts to play the game.
 * 
 * @author Dale Reed 
 * @version February 20, 2009
 */

import java.util.Scanner;

public class PlayGame
{
    /** keyboard is used to handle user input */
    private Scanner keyboard = new Scanner( System.in);
    /** theBoard is used to create a playing board, which in turn keeps track of the pieces */
    private Board theBoard;     // the playing board
    /** moveNumber keeps track of whose move it is, based on odd for "black" and even for "white" */
    private int moveNumber = 1;     
    /** pieceToBeMovedLabel is the label of the piece to be moved */
    int pieceToBeMovedLabel = 0;   
    /** userinput, which can be 'x' to exit, 'r' to randomize board, or a number '1'..'8' */
    String userInput = "";

    
    /**
     * main method chains off to method doIt() to avoid static errors.
     * 
     * @param args  command line arguments, which we're not using
     */
    public static void main(String[] args)
    {
        PlayGame myInstance = new PlayGame(); 
        myInstance.doIt();  // chain off to begin playing
    }
    
    
    /**
     * The "guts" of the program, calling the Board constructor and the loop handling user input.
     *
     */
    void doIt()
    {      
        // Display identifying information
        System.out.println( "Author: Dale Reed \n" +
                            "Program: #3, 9 Tiles Puzzle\n" +
                            "TA: Englebert Humberdink, T 4-5 \n"+
                            "Feb 20, 2009");
        System.out.println();
                            
        // Display game instructions. 
        System.out.println( 
            "Welcome to the 9 tiles puzzle.\n" +
            "On each turn, select a tile to move (1..8) \n" +
            "Once the tiles are in ascending numerical order with the blank square at the \n" +
            "bottom right, then the game ends.  Enter x at any point to exit the game. \n" +
            "Enter 'r' at any point to randomize the board tiles.  Have fun!\n");
    
        theBoard = new Board();     // allocate memory and call the Board constructor
        
        // main loop
        while( gameIsNotDone() ) {
            // prompt for and get user input
            System.out.print(moveNumber + ". Enter square to move: ");
            // read in the piece to be moved (or x to exit)
            userInput = keyboard.nextLine();
            // convert to upper case to simplify comparisons later
            userInput = userInput.toUpperCase();
            
            // check to see if exit ('x') was chosen
            if( userInput.charAt(0)=='X') {
                // user wants to exit
                break;
            }
            // check to see if randomize ('r') was chosen
            if( userInput.charAt(0)=='R') {
                // user wants to randomize the tiles
                theBoard.randomizeBoard();
                continue;
            }
            
            // Getting here means the user wants to make a move, since neither 'x' nor 'r'
            // was chosen.  Convert the first user input character to an integer for subsequent use.
            // This is done by character arithmetic.  I.e. '2' - '0' equals the int value 2
            pieceToBeMovedLabel = userInput.charAt(0) - '0';
            
            // verify that index is within range
            if( (pieceToBeMovedLabel < 1) || (pieceToBeMovedLabel > 8) ) {
                // error, piece is out of range.
                System.out.println("*** Sorry, that piece is out of range.  Please retry. *** ");
                continue;
            }              
            
            // Make the move.  This code returns 0 if successful, -1 otherwise
            if( theBoard.moveSquare( pieceToBeMovedLabel) != 0) {
                // move was invalid
                continue;   // branch back up to retry move  
            } 
            
            // update the move
            moveNumber++;
        }//while (bothPlayersHaveMoreThan3Pieces...    // main loop                   

        System.out.println("Thanks for playing.  Exiting program... ");        
    }//end method doIt()
    
    
    /**
     * See if game is done.
     * Game continues if pieces are not in order
     * 
     * @return          true if tiles are in order, false otherwise
     */
    private boolean gameIsNotDone()
    {
        // verify piece ordering
        return true;
    }
    
    
}// end class PlayGame()